Pharmacokinetics and pharmacodynamics of labetalol in elderly and young hypertensive patients following single and multiple doses.

Abstract

Several physiologic changes accompany the aging process and may alter the pharmacokinetics and pharmacodynamics of drugs given to elderly patients. The primary purpose of the present investigation was to compare the pharmacokinetics of labetalol in young and elderly hypertensive patients. Limited data regarding the pharmacodynamics of labetalol in each of these age groups were also evaluated. Ten young (age 32-48 yrs) and nine elderly (age 60-68 yrs) patients with essential hypertension were evaluated after the first and last doses of a 15-day regimen of labetalol. The young group received 200 mg orally at 9:00 P.M. and 9:00 A.M.; the elderly group received 200 mg once daily at 9:00 P.M. No significant differences in the mean (SD) apparent oral clearance of the drug existed between groups after the first [4.8 (1.9) and 4.3 (1.2) L/hr/kg] and final [4.4 (2.2) and 3.4 (1.0) L/hr/kg] doses of labetalol. No changes in any pharmacokinetic values for labetalol were detected as a function of age. Changes in standing blood pressure and heart rate after the first and last doses were generally similar between the young and elderly hypertensives. Labetalol was effective and well tolerated in both groups.